You can still get proper editor support with Golang (even though it isn't designed for it). I've done so here with VSCode working with a "remote" delve session: https://github.com/cjsaylor/chessbot/blob/11e1059aa77fed84d2...
My point being, if you wanted to execute the following code: https://github.com/cjsaylor/chessbot/blob/11e1059aa77fed84d2...
You probably wouldn't be able to, without restructuring how you're handling your state that is being used there. A REPL driven made program usually is made that the runtime carries the state and exposes it, so you could just select that part and run it, and see the output of it.
I'm guessing delve is more like a traditional debugger that steps through each line, rather than an REPL, correct?
I may be misunderstanding the "true" REPL development here, but I think the points laid out by the article seems to match my experience to a degree.
It seems like a ripe target for an opensource library to accomplish this. I may explore this later on when I have more time to devote.
When everything's well again, I move the bits to a test case.
And you don't need to extract anything into functions, lisp-syntax kind of already gives you all the separation you need, so you can just execute code in place if you need it to.
I think you need to have a language (or structure your particular program in a way) that is really made with live-coding in mind for it to actually give you any benefits, like Smalltalk or Clojure and similar. Otherwise it's just adding another step to reach the real program you're running.
Edit: using your example as an example here, hope you don't mind. A program made with REPL driven development would have way less code in the main function, in order for you to test the code outside with your REPL. The `StoreGame` function would accept a data-store + the argument you have now, so at development-time, you can pass it arbitrary stores. And similar changes.